Serial port trouble

[Kevin Decker]

Gabor,

Opening the port seems to work correctly. I am using CreateFileA to establish the commhandle. Sorry for not including the code before.

RUN CreateFileA (vport,
READ_WRITE,
0,
0,
OPEN_EXISTING,
0,
0,
OUTPUT CommHandle).
IF CommHandle < 0 THEN DO:
MESSAGE
"Invalid comm handle:" CommHandle
VIEW-AS ALERT-BOX ERROR.
QUIT.
END.

SET-SIZE(DCBStructurePointer) = 29.
RUN GetCommState (CommHandle,
INPUT-OUTPUT DCBStructurePointer,
OUTPUT nRC).

IF nRC <>0 THEN DO:
ASSIGN DCBStructure = GET-STRING(DCBStructurePointer,1).
PUT-LONG(DCBStructurePointer,5)=9600.
bit-flags=EXP(2,9) + EXP(2,10).
PUT-LONG(DCBStructurePointer,9)=bit-flags.
PUT-BYTE(DCBStructurePointer,19)=8.
PUT-BYTE(DCBStructurePointer,20)=0.
RUN SetCommState (CommHandle,
INPUT-OUTPUT DCBStructurePointer,
OUTPUT nRC).
IF nRC=0 THEN
MESSAGE
"error setting new parameters"
VIEW-AS ALERT-BOX.
END.

Thanks,
Kevin

 

[Gabor Topor]

Kevin,

Have you checked event log?

Regards,
Gabor

 

[Kevin Decker]

Gabor,

I had not thought to check the event log previously. Great idea, but it does not contain any entries related to my problem.

Thanks,
Kevin

 

[Gabor Topor]

Kevin,

Unfortunatelly we have not got Windows 2000, but I could test the code on Win98 and Windows XP. It works fine.

I could not find any usefull information except one thing might help you. Many programs set timouts before calling GetCommstate. E.g.:

hCom = CreateFile(ComName.c_str(), GENERIC_READ|GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED, 0);
SetupComm(hCom, 2048, 2048);

GetCommTimeouts(hCom, &Timeouts);
Timeouts.ReadIntervalTimeout = MAXDWORD;
Timeouts.ReadTotalTimeoutMultiplier = 0;
Timeouts.ReadTotalTimeoutConstant = 0;
Timeouts.WriteTotalTimeoutMultiplier = 0;
Timeouts.WriteTotalTimeoutConstant = 0;
ierr = SetCommTimeouts(hCom, &Timeouts);

GetCommState(hCom, &dcbBuf);


It might help you also.


Best regards,
Gabor

 

[Kevin Decker]

Gabor,

Thank you for all your help, I will try the timeouts. Additionally, I know that Win 2000 has alot more security issues to deal with, so I will be researching if it is a 'permission' issue. However I am already logged in as Administrator. so I don't expect much.

Thanks,
Kevin